Automatic variable power transmission



2 Sheets-Sheet 1 5. DE LAVAUD Filed Jan. 28, 1922 AUTOMATIC VARIABLEPOWER TRANSMISSION (If I! If A mw w 2 Sheets-Sheet 2 r Jam May 5, 1925.1 I D. 5. DE LAVAUD AUTOMATIC VARIABLE POWER TRANSMISSION Filed Janp28,1922 Patented May 5, 1925.

PAT ENT OFFICE.

DIMI'IRI SENSAIID DE LAVAUD, OF PARIS, FRANCE.

AUTOMATIC VARIABLE POWER TRANSMISSION.

Application filed January 28; 1922. Serial No. 532,468.

To all w/mm i/mayroller/'11:

Be it known that l Dmrrm Snxsmn on LAvAm), a citizen of the UnitedStates of Brazil, and resident of the city of Paris, in the Republic ofFrance, have invented certain new and useful Improvements in AutomaticVariable Power 'lransmission', described in the following specification.and illustrated in the accompanying drawings that form part ofithe same.

The principal objects of this invention are to improve the generalconstructitm of the 3 invention disclosed in my companion applicationNo. 532,4 62, til ed January 28th" 1922, and particularly to provideatransmission device in'whieh the speed of the driven member. 'will varyautomatically in direct proportion to the torque, thereby eliminatingthe necessity of providing a manually controlled device for regulatingthe ratio between the driving and driven members.

The principal feature of the invention consistsin' inter-posing abalancing medium to automatieall etleet a change in the angularitv ofthe axis of the oscillating member in, direct proportion to the torqueof the driven member. thereby automaticall adjusting the throw ot themembers for operating' the driven member and changing the gear ratio.

A l'nrther important l eature consists in the novel construction oi theoscillating member and ot the bearing supports for the driving shalt.

still "further importantfeature consists in the novel arrangement ofmechanism vfor allowing a differential action in a divided drivenmember. i

in the drawings Figure l is a longitudinal vertical mid-section of myimproved trans-.

mission.

lligure .5 is a vertical mid-sectional view through the line .Z-" ofFigure .l.

The construction shown is applied to a motor car drive and the casinglenclosesthe propeller shaft 2 and rear axle 2*, torming an oil tightchamber. Within the forward end of 'the casing are arranged the thrustbearings tand 5 and the bearings (3 which support the sleeve 7 in whichthe shaft 2 is slid ablv mounted.

The shaft 2 is formed With a spherical enlargement 8 upon which ismounted a concentric sheave 9 which oscillates on the trunnion pin 10.The sheave is provided with a lug 11 which is pivotally secured in a jaw12 on the adjacent end of the sleeve 7 and thus connects the shaft,sheave and sleeve to rotate together. The rear end 13 of the shaft issupported in a bearing 14 in which it is free to slide.

A ring 15 is secured to the forward end of the sleeve and bears on thethrust bearing 4, thus holding the sleeve from longitudinal movement.

A helical compression spring 16 encircles the sha'tt 2 and bears againstthe ring 15 and adgastmg nuts 17 on the shaft engage the apex of thespring and the shattiis thus normally held in the forward position withthe axis of the sheave 9 at its greatest angular ity. L

The driven shaft 18 is" rotated through a ratchet device, the operatingrings 19 of which are connected by the rods 20 to a ring 21 mounted onanti-friction bearings on the sheave 9.

As the driving shaft rotates. the sheave 9 by reason of the angularityof its axis. oscillates and imparts a reciprocating motion to the rods20 which in turn rotate the driven shaft through the ratchet mechanismand the speed of rotation of the driven member will vary according asthe axis of the sheave varies in its angular relation to the shaft.-

Vhen there is no load on the driven shaft, the spring 16 holds the shaft2 in the forward position as shown but when load is applied to thedriven shaft the resistance to rotation opposes the pull of the rods 20and tends to shift the angularit-y of the axis of rotation of the sheaveand the pull is transmitted to the shaft 2 through the trunnion supportsof the sheave. This movement is opposed bv the spring 16 and itsresistance increases in direct proportion to the increase of the torqueof the driven shaft. As the torque increases the angularitv of the axis0t rotation of the sheave'is shifted closer into line with the axis ofthe driving shaft and the oscillations of the sheave are of lesserlength, consequentlv the throw of the rods 20 is lessened and the speedis reduced. An

automatic change of the ratio between the driving and driven shafts isthus efiected and it will be readily seen that this ratio has a fullrange from full speed to zero. The

consequence of this is that the 'ratio will antomatically adjustaccording to the power and the load and there will be no waste, The

result of such achivement will be a direct economy of power with aconsequent saving of fuel.

Further, the changing of gears is eliminated and the very undesirablecondition of disconnecting the driven shaft from the driving power isobviated and a practically perfect condition of control is achieved.That is to say, in the operation of motor cars, the engine may bethrottled down to any speed as required in congested traffic and whenacceleration is required there will he no change of gears necessary. Theacceleration of the engine is merely increased until the required powerto overcome the inertia of the load is transmitted and the desired speedof the car is attained. This dispenses entirely with racing the engineand the attendant evils.

In the adaptation of this invention to the driving mechanism for a motorcar, it is necessary to provide for the inequalities in the conditionsof travel, that is to say, there must he a differential action betweenthe driving wheels and one must be free to move independent of theother.

In the drawings herewith the axle or driven shaft 18 is dividedcentrally and oncircling the end of each member is a sleeve 2-2 which issupported in suitable bearings :23 within the casing 1. Inch of thesleeves 2:2 is. providewith a ratchet surface to which rotation iscommunicated by the rollers which are in turn driven by the ratchetmechanism directly connected with the rods 20.

The arrangement of this secondary atchet provides a communicationbetween the driving mechanism and the axle which will permit eitherwheel to turn in a for ward direction frce of the other, consequent- 1vas the motor car travels one wheel may travel freely in advance of theother, thus allowing a perfect dificrential action.

it will be noted that in such differential action the power is appliedby the slower moving or inside whccl.

Tn the operation of a motor car equipped with a traIr mis;-=ion such asdescribed, it may be desirable to havoavailable means for n'iai'iuallvcontrolliiig the power ratio and such a means is illustrated inthc formof a pedal cam 26 suitably mounted and adapted to engage a collar 27 onthe driving shaft. lrcr-z urc upon the pedal will rotate the rain toeffect the compression of the balancing spring which will have the effrt of shifting the axis of rotation of the o illating mcmbcrthuscrcating a variation in illo ower ratio between the driving and drivenmcn'ibcrs,

What I claim as my invention is:-

1. In a variable power transmission, a driven shaft, a longitudinallymovabledrivingshaft, an oscillating member rotatable with-the drivingshaft and operatively connccted with the driven shaft, and a springmcd'i'nm exerting a longitudinal pressure on the driving shaft inopposition to the torque of the drivcn shaft. 4

2. In a variable power transmission, a driven member, an oscillatingmember operativelv conne ted with the driven member, alfillglilltlllltllly movable driving shaft, an oscillating memberrotatable with the driving shaft and pivoted on an axis transversethereof. a member adapted to rotate in a fixed plane and pivotallyconnected to the rotatable oscillating member. and a balancing mediumexerting a longitudinal force against said driving shaft tending tovholdthe axis of said rotating oscillating member in angular relation to theaxis of rotation of the driving sha ft.

3. In a variable power transmission, a driven member. a noirrotatableoscillating member operaiivclv connected with the driven member, alongitudinally movable driving shaft, :1 member rotatably connected withthe i'lriving shaft and adapted to oscillate thereon, a member rotatablewith the driving sha ft and held from axial movement and pivotallyconnected at one side of the axis of the rotatable oscillating membercarried by the driving shaft, and a balancing member cxrrting alongitudinal pressure upon the driving shaft to hold the oscillatingnumber with its axis of rotation in angular relation to the-axis of thedriving shaft in opposition to the torque of the driven member.

4. in a variable power transmission, a driven member, an oscillatingmember on eratively connected with the driven member,'a longitudinallymovable driving shaft, a member rotatably connected with the drivingshaft and adapted to oscillate thereon, a member rotatable with thedriving shaft and held from axial movement and pivotally onnected at oneside of the axis of the rotatable oscillating member carried by thedriving shaft. and a spiral compression spring encircling the. drivingshaft and ex crting a longitudinal pressure thereon to hold theoscillating members with their respective axes of rotation in angularitywith the driving membe and effecting an automati balance between thedriving pow r and the torque of the driven member.

5. In a variable power tiansmission, a casing. a sleeve member rotatablymounted in said casing and held from longitudinal movement. a drivingshaft slidahly arran ed in said sleeve. a spiral compression springencircling said driving shaftf atone end of the sleeve, and adjustablecontact on the driving shaft engaging said spring, an ossaid oscillatingmember and non-rotatively oillating member pivoted on the end of theheld to oscillate therewith, and means condriving shaft 0p osite to thes ring, a. proneoting said ring with the driven member to 10 jectioncarried iiy .the rotata le sleeve, :1 impart rotative action theretothrough its 5 member rigid 'witlithe oscillating member oscillations.

pivotally conneotedwiththerprojection from said sleeve, a ring rotatablymounted on DIMITRI SENSAUD DE LAVAUD.

